RIBA_HAMD5
ID RIBA_HAMD5 Reviewed; 196 AA.
AC C4K8Q4;
DT 22-SEP-2009, integrated into UniProtKB/Swiss-Prot.
DT 07-JUL-2009, sequence version 1.
DT 03-AUG-2022, entry version 55.
DE RecName: Full=GTP cyclohydrolase-2 {ECO:0000255|HAMAP-Rule:MF_00179};
DE EC=3.5.4.25 {ECO:0000255|HAMAP-Rule:MF_00179};
DE AltName: Full=GTP cyclohydrolase II {ECO:0000255|HAMAP-Rule:MF_00179};
GN Name=ribA {ECO:0000255|HAMAP-Rule:MF_00179}; OrderedLocusNames=HDEF_0118;
OS Hamiltonella defensa subsp. Acyrthosiphon pisum (strain 5AT).
OC Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC Enterobacteriaceae; aphid secondary symbionts; Candidatus Hamiltonella.
OX NCBI_TaxID=572265;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=5AT;
RX PubMed=19451630; DOI=10.1073/pnas.0900194106;
RA Degnan P.H., Yu Y., Sisneros N., Wing R.A., Moran N.A.;
RT "Hamiltonella defensa, genome evolution of protective bacterial
RT endosymbiont from pathogenic ancestors.";
RL Proc. Natl. Acad. Sci. U.S.A. 106:9063-9068(2009).
CC -!- FUNCTION: Catalyzes the conversion of GTP to 2,5-diamino-6-
CC ribosylamino-4(3H)-pyrimidinone 5'-phosphate (DARP), formate and
CC pyrophosphate. {ECO:0000255|HAMAP-Rule:MF_00179}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=GTP + 4 H2O = 2,5-diamino-6-hydroxy-4-(5-phosphoribosylamino)-
CC pyrimidine + formate + 3 H(+) + 2 phosphate; Xref=Rhea:RHEA:23704,
CC ChEBI:CHEBI:15377, ChEBI:CHEBI:15378, ChEBI:CHEBI:15740,
CC ChEBI:CHEBI:37565, ChEBI:CHEBI:43474, ChEBI:CHEBI:58614; EC=3.5.4.25;
CC Evidence={ECO:0000255|HAMAP-Rule:MF_00179};
CC -!- COFACTOR:
CC Name=Zn(2+); Xref=ChEBI:CHEBI:29105;
CC Evidence={ECO:0000255|HAMAP-Rule:MF_00179};
CC Note=Binds 1 zinc ion per subunit. {ECO:0000255|HAMAP-Rule:MF_00179};
CC -!- PATHWAY: Cofactor biosynthesis; riboflavin biosynthesis; 5-amino-6-(D-
CC ribitylamino)uracil from GTP: step 1/4. {ECO:0000255|HAMAP-
CC Rule:MF_00179}.
CC -!- SUBUNIT: Homodimer. {ECO:0000255|HAMAP-Rule:MF_00179}.
CC -!- SIMILARITY: Belongs to the GTP cyclohydrolase II family.
CC {ECO:0000255|HAMAP-Rule:MF_00179}.
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DR EMBL; CP001277; ACQ66891.1; -; Genomic_DNA.
DR RefSeq; WP_012737856.1; NC_012751.1.
DR AlphaFoldDB; C4K8Q4; -.
DR SMR; C4K8Q4; -.
DR STRING; 572265.HDEF_0118; -.
DR EnsemblBacteria; ACQ66891; ACQ66891; HDEF_0118.
DR GeneID; 66260055; -.
DR KEGG; hde:HDEF_0118; -.
DR eggNOG; COG0807; Bacteria.
DR HOGENOM; CLU_020273_2_1_6; -.
DR OMA; GQGFILY; -.
DR UniPathway; UPA00275; UER00400.
DR Proteomes; UP000002334; Chromosome.
DR GO; GO:0005525; F:GTP binding; IEA:UniProtKB-KW.
DR GO; GO:0003935; F:GTP cyclohydrolase II activity; IEA:UniProtKB-UniRule.
DR GO; GO:0008270; F:zinc ion binding; IEA:UniProtKB-UniRule.
DR GO; GO:0009231; P:riboflavin biosynthetic process; IEA:UniProtKB-UniRule.
DR CDD; cd00641; GTP_cyclohydro2; 1.
DR Gene3D; 3.40.50.10990; -; 1.
DR HAMAP; MF_00179; RibA; 1.
DR InterPro; IPR032677; GTP_cyclohydro_II.
DR InterPro; IPR000926; RibA.
DR InterPro; IPR036144; RibA-like_sf.
DR Pfam; PF00925; GTP_cyclohydro2; 1.
DR SUPFAM; SSF142695; SSF142695; 1.
DR TIGRFAMs; TIGR00505; ribA; 1.
PE 3: Inferred from homology;
KW GTP-binding; Hydrolase; Metal-binding; Nucleotide-binding;
KW Reference proteome; Riboflavin biosynthesis; Zinc.
FT CHAIN 1..196
FT /note="GTP cyclohydrolase-2"
FT /id="PRO_1000203813"
FT ACT_SITE 126
FT /note="Proton acceptor"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
FT ACT_SITE 128
FT /note="Nucleophile"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
FT BINDING 49..53
FT /ligand="GTP"
FT /ligand_id="ChEBI:CHEBI:37565"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
FT BINDING 54
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /ligand_note="catalytic"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
FT BINDING 65
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /ligand_note="catalytic"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
FT BINDING 67
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /ligand_note="catalytic"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
FT BINDING 70
FT /ligand="GTP"
FT /ligand_id="ChEBI:CHEBI:37565"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
FT BINDING 92..94
FT /ligand="GTP"
FT /ligand_id="ChEBI:CHEBI:37565"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
FT BINDING 114
FT /ligand="GTP"
FT /ligand_id="ChEBI:CHEBI:37565"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
FT BINDING 149
FT /ligand="GTP"
FT /ligand_id="ChEBI:CHEBI:37565"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
FT BINDING 154
FT /ligand="GTP"
FT /ligand_id="ChEBI:CHEBI:37565"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00179"
SQ SEQUENCE 196 AA; 22247 MW; 385B6A258C391169 CRC64;
MNLKRISEAK LPTPWGDFLM IGFKELDKEQ DHLALVLGDI STDAPVLSRI HSECLTGDAL
FSLRCDCGFQ LKAAFKQICE EKRGLLIYHR QEGRNIGLLN KIRAYALQDQ GADTVEANHQ
LGFATDERDF TVCANIYKIL DVKAIRLLTN NPEKIKILKK EGINVVQRVS LIVESNPNNQ
DYLSTKKNKM GHFFKK
